2,2-dibromo-3-nitrilopropionamide and hexachlorodimethylsulfone as a slime control composition

ABSTRACT

The present invention relates to certain processes and compositions useful for inhibiting the growth of slime in water and, in particular, water used for industrial purposes; for example, in the manufacture of pulp paper, in the manufacture of paper, in cooling water systems and in effluent water treatment. The novel processes and compositions of the present invention are processes or mixtures which show unexpected synergistic activity against microorganisms, including bacteria, fungi and algae, which produce slime in aqueous systems or bodies which are objectionable from either an operational or aesthetic point of view. Specifically the invention is directed to the use of compositions comprising a combination of 2-2-dibromo-3nitrilopropionamide and hexachlorodimethyl sulfone.

United States Patent Shema et al.

July 22, 1975 [75] Inventors: Bernard F. Shema, Glenside; Robert H.Brink, Jr., Doylestown; Paul Swered, Philadelphia, all of Pa.

[73] Assignee: Betz Laboratories, Inc.. Trevose. Pa.

[22] Filed: June 28, I973 [21} Appl. No.1 374,582

[52] US. Cl. 424/304; 210/64; 252/180 [51] Int. Cl. AOIN 9/06 [58] Fieldof Search l. 252/180 l06; 424/337, 424/304; 210/64 [56] References CitedUNITED STATES PATENTS Z 692.? l0/l954 Stayncr ct a] 252/855 D 2,959.5l7ll/l96() Bowers i 4 l l 252/lG6 3.557.184 l/l97l Toepfl 260/4654 PrimaryExaminer-Benjamin R. Padgett Assislant Examiner-Deborah L. KyleAtturney, Agent, or Firm-Alexander D. Ricci [57] ABSTRACT The presentinvention relates to certain processes and compositions useful forinhibiting the growth of slime in water and, in particular, water usedfor industrial purposes; for example, in the manufacture of pulp paper,in the manufacture of paper, in cooling water systems and in effluentwater treatment. The novel processes and compositions of the presentinvention are processes or mixtures which show unexpected syner gisticactivity against microorganisms, including bacteria, fungi and algae,which produce slime in aqueous systems or bodies which are objectionablefrom either an operational or aesthetic point of view. Specifically theinvention is directed to the use of compositions comprising acombination of 2-2-dibromo-3- nitrilopropionamide and hexachlorodimethylsulfone.

8 Claims, N0 Drawings 2.2-DIBROMO-3-NITRILOPROPIONAMIDE ANDHEXACHLORODIMETHYLSULFONE AS A SLIME CONTROL COMPOSITION BACKGROUND OFTHE INVENTION The formation of slime by microorganisms is a problemwhich attends many systems. For example. lagoons. lakes. ponds. pools.and such systems as cooling water systems and pulp and paper millsystems all possess conditions which are conducive to the growth andreproduction of a slime-forming microorganisms. in both once-through andrecirculating cooling systems. for example. which employ largequantities of water as a cooling medium. the formation of slime bymicroorganisms is an extensive and constant problem.

Airborne organisms are readily entrained in the water from coolingtowers and find this warm medium an ideal environment for growth andmultiplication. Aerobic and heliotropic organisms fluorish on the towerproper while other organisms colonize and grow in such areas as thetower sump and the piping and passages of the cooling system. Such slimeserves to deteriorate the tower structure in the case ofwooden towers Inaddition. the deposition of slime on metal surfaces promotes corrosion.Furthermore. slime carried through the cooling system plugs and foulslines. valves. strainers. etc. and deposits on heat exchange surfaces.in the latter case. the impedance of heat transfer can greatly reducethe efficiency of the cooling system.

in pulp and paper mill systems. slime formed by microorganisms is alsofrequently and. in fact. commonly encountered. Fouling or plugging byslime also occurs in the case of pulp and paper mill systems. Of greatersignificance. the slime becomes entrained in the paper produced to causebreakouts on the paper machines with consequent work stoppages and theloss of production time or unsightly blemishes in the final productwhich results in rejects and wasted output. The previously discussedproblems have resulted in the extensive utilization of biocides incooling water and pulp and paper mill systems. Materials which haveenjoyed widespread use in such applications include chlorine organomercurials. chlorinated phenols. organobromines, and variousorgano-sulfur compounds. All of these compounds are generally useful forthis purpose but each is attended by a variety of impediments. Forexample. chlorination is limited both by its specific toxicity forslime-forming organisms at economic levels and by the ability ofchlorine to react which results in the expenditure of the chloringbefore its full biocidal function may be achieved. Other biocides areattended by odor problems and hazards in respect to storage. use orhandling which limit their utility. To date. no one compound or type ofcompound has achieved a clearly established predominance in respect tothe applications discussed. Likewise. lagoons. ponds. lakes. and evenpools. either used for pleasure purposes or used for industrial purposesfor the disposal and storage of indus trial wastes, become. during thewarm weather. besieged by slime due to microorganism growth andreproduction. ln the case of the recreational areas. the problem ofinfection. etc. is obvious. in the case of in dustrial storage ordisposal of industrial materials. the microorganisms cause additionalproblems which must be eliminated prior to the materials use or thewaste is treated for disposal.

Naturally. economy is a major consideration in respect to all of thesebiocides. Such economic considerations attach to both the cost of thebiocide and the expense of its application. The cost-performance indexof any biocide is derived from the basic cost of the material. itseffectiveness per unit of weight. the duration of its biocidal orbiostatic effect in the system treated, and the ease and frequency ofits addition to the system treated. To date, none of the commerciallyavailable biocides have exhibited a prolonged biocidal effect. Instead.their effectiveness is rapidly reduced as the result of exposure tophysical conditions such as temperature. association with ingredientscontained by the system toward which they exhibit an affinity orsubstantivity, etc.. with a resultant restriction or elimination oftheir biocidal effectiveness.

As a consequence, the use of such biocides involves their continuous orfrequent addition to systems to be treated and their addition to aplurality of points or zones in the systems to be treated. Accordingly,the cost of the biocide and the labor cost of such means of applying itare considerable. In other instances. the difficulty of access to theZone in which slime formation is experienced precludes the effective useof a biocide. For example. in a particular system there is no access toan area of which slime formation occurs and it may only be applied at apoint which is upstream in the flow system. However. the physical orchemical conditions. e.g.. chemical reactivity. thermal degradation.etc. which exist between the point at which the biocide may be added tothe system and the point at which its biocidal effect is desired renderthe effective use of a biocide impossible.

Similarly. in a system experiencing relatively slow flow. such as apaper mill, if a biocide is added at the beginning of the system. itsbiocidal effect may be com pletely dissipated before it has reached allof the points at which this effect is desired or required. As aconsequence, the biocide must be added at a plurality of points. andeven then a graduated biocidal effect will be experienced between onepoint of addition to the system and the next point downstream at whichthe biocides may be added. In addition to the increased cost ofutilizing and maintaining plural feed points, gross ineconomies inrespect to the cost of the biocide are experienced. Specifically, ateach point of addition, an excess of the biocide is added to the systemin order to compensate for that portion of the biocide which will beexpended in reacting with other constituents present in the system orexperience physical changes which im pair its biocidal activity.

It is an object of the present invention to provide methods andcompositions for controlling slimeforming microorganisms in aqueoussystems such as cooling water systems and pulp and paper mill systems,and for controlling slime formation or microorganisms populations inaqueous bodies in general. Moreover. another object of the invention isthe provision of methods and compositions for controlling slimeformingmicroorganisms in any aqueous system which is conducive to the growthand reproduction of microorganisms and. in particular. cooling water andpaper and pulp mill systems which employ a combination of2.B-dibromo-3-nitrilopropionamide dhtl Hexachlorodimethylsulfone.

in practice of the invention. the combination is added to the particulafsystem being treated for example.

cooling water systems, paper and pulp mill systems, pools. ponds,lagoons, lakes, etc. in a quantity adequate to control the slime-formingmicroorganisms which are contained by. or which may become entrained in,the system which is treated. It has been found that such compositionsand methods control the growth and oc currence of such microorganisms asmay populate these particular systems.

2-2-dibromo-3-nitrilopropionamide (hereafter DBNP) is available as anantimicrobial agent, Dow XD-7287L of the Dow Chemical Company andHexachlorodimethyl sulfone is available as N-] 386 from the StaufferChemical Company.

As earlier stated, the inventive compositions are comprised of thelatter compounds, either compound being present in such a quantity as toimpart a synergistic behavior to the composition as a whole, the weightratio of the amide to the sulfone ranging from about 95:5 to about 5:95vWhen these two ingredients are mixed, the resultng mixtures possess ahigh degree of slimicidal activity which could not have been predictedbeforehand from the known activity of the individual Q, Q 1 issyncrgism, l is antagonism. and l is Q" Q addltlvity where,

Q,. Quantity of Compound A, acting alone, producing an end point 0,,Quantity of Compound B, acting alone, producing an end point Q, Quantityof Compound A. in the mixture, producing an end point Q Quantity ofCompound B, in the mixture, producing an end point For mixtures ofCompounds A and B, and for Compound A and Compound B acting alone. thefollowing results were observed. Summary of synergistic activity ofvarying percentages of Compound A and Compound B:

SYNERGISTIC COMBINATION Compound A: 2-2-dibromo-3-nitrilopropionamideCompound B: Hexachlorodimethyl sulfone TABLE I TEST ORGANISM AERQBACTERAEROGENES ingredients comprising the mixture. Accordingly, it istherefore possible to produce a more effective slimecontrol agent thanhas previously been available. Because of the enhanced activity of themixture. the total quantity of the biocide required for an effectivetreatment may be reduced. In addition, the high degree of biocidaleffectiveness which is provided by each of the ingredients may beexploited without use of the higher concentrations of each.

To demonstrate the synergism which is provided by the inventivecombinations of compounds, the data as set forth in the Table below wasdeveloped.

EXAMPLE l Synergism was demonstrated by adding Compound A and Compound Bin varying ratios and over a range of concentrations to liquid nutrientagar medium (Tryp' tone Glucose Extract Agar) at approximately 50C.After the medium had solidified in Petri plates, it was inoculated witha bacterial suspension. Following two days incubation, the lowestconcentration of each ratio which prevented growth on the agar mediumwas taken as the end point. End points for the various mixtures werethen compared with end points for the pure active ingredients workingalone in concomitantly prepared agar medium plates. Synergism wasdetermined by the method described by F. C. Kull, P. C. Eisman, H. D.Sylwestrowicz and R. L. Mayer, APPLIED MICROBI- OLOGY, 9, 538-41, I946).and the relationships.

The mode of establishing the synergistic behavior of the compositions ofthe present invention is a widely used and an industrially acceptableprocedure. Although it is believed that the above is sufficient inexplaining the procedure, for a further description thereof referencecan be made to U.S. Pat. No. 3,23 l ,509 and its file history where dataof this nature was considered to be acceptable. Moreover, the article byKull et al published in APPLIED MICROBIOL OGY, 9, 538-54l, will furnishadditional information in this regard.

For the testing to ascertain synergistic behavior, Aerobacter aerogeneswas favored since this microorganism is found to exist and found to bemost troublesome in pulp and paper producing processes, as well as incooling towers. Moreover, this microorganism is difficult to controland/or kill and accordingly its existence does give rise to troublesomeslime. In view of the foregoing, it can then be appreciated that sinceAerohaczer aerogencs is prevalent in most slime-affected systems andsince this microorganism is difficult to control or kill, that oncecontrol of this microorganism is maintained, then for all practicalpurposes the total microorganism population with its different types isconsidered controlled.

When the inventive compositions are employed in the treatment of coolingor paper mill water, they are preferably utilized in the form ofrelatively dilute solutions or dispersions. For example. a preferredsolution comprises between 5 to by weight of the synergistic combinationin admixture with various solvents and solubilizing agents.

Surfactants such as the alkylaryl polyether alcohols, polyetheralcohols, alkyl benzene sulfonates and sulfates, and the like, may alsobe employed to enhance the dispersibility and stability of theseformulations. The foregoing solutions of the biocidal compositions areutilized in order to insure the rapid and uniform dispersibility of thebiocides within the industrial water which is treated. it has been foundthat either aqueous or non-aqueous solvents are generally suitable inthe preparation of compositions of the invention. For example, organicsolvents such as methyl cellosolve and aliphatic and aromatichydrocarbons, e.g., kerosene, can be used quite successfully. Based uponthe synergism study as outlined above. it was ascertained that in thetreatment of paper mill and cooling water, effective biocidal action isobtained when the concentration or treatment level of the combination oradmixture of biocides is between 0.5 parts per million to I000 parts permillion, and preferably between I and I parts per million, based uponthe total content of the system treated, such as the total quantity ofcooling water or paper mill water.

The compositions may also be utilized for the preservation of slurriedand emulsions containing carbohydrates, proteins, fats, oils, etc.Dosage levels for this purpose range in the vicinity of 0.01 to Thecompositions of the invention which can be prepared by merely combiningthe respective ingredients and mixing thoroughly at standard conditionsmay be fed continuously to the treated system, c.g., by means of ametered pump, or may be fed periodically at intervals calculated tocontrol the growth of slime-forming organisms in the system. Naturally,in the treatment of cooling water the feeding of the inventivecompositions must be designed to compensate for blowdown in thosesystems which employ that expedient.

As would be expected, the inventive composition may be added to thecooling water or paper and pulp mill systems at any convenient point.Naturally, in once-through or non-circulating systems, the compositionmust be added upstream from the point or points at which microorganismcontrol is desired. In circulating systems or pulp and paper systems,the compositions may be added at any point provided that the time lapseand the conditions experienced between point of addition and the pointat which the effect of the composition is experienced are not so drasticas to result in the neutralization of the effect of the composition.

SLIME CONTROL EFFECTIVENESS The inventive methods and materials weretested with respect to their performance in the control of slimeformation in industrial systems, In this test an industrialrecirculating water was obtained from a system which was currentlyexperiencing problems in respect to the formation of slime bymicroorganisms. Such tests do not demonstrate the efficiency of thebiocide employed with respect to specific species of microorganisms butinstead supply a practical demonstration of the efficacy of the biocidetested in relation to those communities of microorganisms which haveevidenced their ability to form slime in actual industrial systems.

In testing of recirculating water samples, a substrate evaluation wasemployed, In such testing, identical portions of water samples aretreated with varying concentrations of biocide and two portions are leftuntreated to serve as controls. The control portions are plated fortotal count at the beginning of biocide treatment and all portions areplated for total count at some suitable time period (s) after beginningbiocide treatment. Using the counts obtained from the platings, thepercentage kill (based on the initial control count) may be calculated.In the following example, the water sample was taken from a headboxsample taken from a mill located in the north central portion of theUnited States.

For the purposes of comparison, a composition of this invention wasevaluated with two recognized commercial biocides.

EFFICACY RELATIVE TO FUNGI In order to ascertain whether in fact theinventive compositions were effective in controlling fungi, evalu ationswere made following the procedure described by Shema et al, JOURNAL FORTHE TECHNICAL AS' SOCIATION OF THE PULP AND PAPER INDUS- TRY," 36,20A-30A, l953. The described procedure generally entails incorporatingthe biocide under test in a nutrient substrate such as agar, malt, etc.and pouring the resulting medium in a Petri dish and allowing the mediumto solidify. A button of fungus inoculum is placed on the surface of thesolidified medium and the medium is incubated for a period of l4 days.After the period, the diameter of the colony is measured and comparedwith the diameter of the button of inoculum originally placed upon thesurface. If there is no in crease in the diameter, the growth of thefungus is considered to be completely inhibited and the treatment levelwhich effectuates this is considered the inhibitory concentration.

The fungi species utilized as the test microorganism to evaluate theefficacy of the present compositions were Penicillium expansum andAspergillus niger. The study revealed that the above l0% activecomposition of this invention inhibited the growth of Penicilliumexpansum at a treatment level of ppm and 700 ppm completely inhibitedthe growth of Aspergillus niger.

BACTERICIDAL EFFECTIVENESS The bactericidal effectiveness of a l/lmixture of the two components of this invention 10% active) isdemonstrated by the following data in which the inhibiting power isshown in comparison with a commercial biocide. Aerobacler aerogenes wasemployed as the test or- Inhibition Biocidc Materials quantity (ppm) l.2-2-dihromo3-nitrilopropionamidc lllt) hcxachlorodimethyl sulfone lnert(90% 2. RX-3R Accordingly, since the waters of pulp and paper mills andthe water of cooling water systems generally predominately containbacteria such as Aerohacter aerogenes and some fungi such as Penicilliumexpansum and Aspergillus niger, it is apparent from the foregoingevaluations and studies that the inventive composition will effectuatethe claimed objective of controlling microorganisms of aqueous systems.

It should be noted that while the preponderance of evidence has beenderived from the treatment of samples taken from paper and pulp millaqueous systems, the compositions and methods of the present inventionare broadly applicable to the treatment of aesthetic waters as well asindustrial waters such as cooling waters which are plagued by depositsformed by slime-forming organisms, or by the very presence of suchorganisms. Having thus described the invention, what is claimed l. Acomposition for the control of Aerobacter aerogenes in aqueous systemscomprising 2-2-dibromo-3- nitrilopropionamide and hexachlorodimethylsulfone, wherein the weight ratio of the amide to the sulfone rangesfrom about 95:5 to about 5:95 respectively.

2. The composition of claim 1 where said ratio is about :50.

3. A method for controlling the growth of Aerobacter aerogenes in anaqueous system which comprises adding to said system an effective amountof a composition comprised of 2-2-dibromo-3-nitrilopropionamide andhexachlorodimethyl sulfone, wherein the weight ratio of the amide to thesulfone ranges from about :5 to about 5:95 respectively.

4. The method of claim 3 where said ratio is about 5. The method ofclaim 3 wherein said composition is added to said system in an amount offrom about 0.1 to about lOOO parts per by weight of said composition permillion parts by weight of said aqueous system.

6. The method of claim 5 where said composition amount is from about lto about lOO parts per million of said aqueous system.

7. The method of claim 5 wherein the aqueous system is that of a coolingwater system.

8. The method of claim 5 wherein the aqueous system is that of a pulpand paper mill system.

1. A COMPOSITION FOR THE CONTROL OF AEROBACTER AEROGENES IN SQUEOUSSYSTEMS COMPRISING 2-2-DIBROMO-3-NITRILOPROPIONAMIDE ANDHEXACHLORODIMETHYL SULFONE, WHEREIN THE WEIGHT RATIO OF THE AMIDE TO THESULFONE RANGES FROM ABOUT 95:5 TO ABOUT 5:95 RESPECTIVELY.
 2. Thecomposition of claim 1 where said ratio is about 50:50.
 3. A method forcontrolling the growth of Aerobacter aerogenes in an aqueous systemwhich comprises adding to said system an effective amount of acomposition comprised of 2-2-dibromo-3-nitrilopropionamide andhexachlorodimethyl sulfone, wherein the weight ratio of the amide to thesulfone ranges from about 95:5 to about 5:95 respectively.
 4. The methodof claim 3 where said ratio is about 50:50.
 5. The method of claim 3wherein said composition is added to said system in an amount of fromabout 0.1 to about 1000 parts per by weight of said composition permillion parts by weight of said aqueous system.
 6. The method of claim 5where said composition amount is from about 1 to about 100 parts permillion of said aqueous system.
 7. The method of claim 5 wherein theaqueous system is that of a cooling water system.
 8. The method of claim5 wherein the aqueous system is that of a pulp and paper mill system.